1. Field of the Invention
This invention pertains to the field of golf clubs.
2. Description of the Related Art
Golf is a familiar game in which players use long-shafted clubs to strike golf balls to drive them down a fairway, onto a green and into a cup located on the green. The golf "system" comprises three elements: the golfer, the golf club, and the golf ball. As noted, the present invention pertains to the golf club.
Golfers seek golf clubs that provide control and power. A superior golf club will allow a skilled golfer to hit a golf ball straight and far. The most important parameter in achieving these goals is the skill of the golfer. However, the performance of the golf club is also a significant factor. In particular, the response of the golf club due to impact with the golf ball affects the direction and range of the golf ball.
Traditionally, golf clubs are divided into two types, drivers and irons. Until recently, drivers were long shafted clubs having bulbous heads with a metal or plastic face fastened to the wood. In contrast, irons have somewhat shorter shafts and an all metal head that is often substantially planar along front and back surfaces. Irons are used for fairway shots and where substantial ball control is necessary, such as when chipping onto a green or putting.
Drivers have undergone many recent innovations including the advent of metal drivers, sometimes called "metal woods." The metal drivers have a similar shape as the traditional wood drivers, but the head size has increased. The new metal drivers are typically one-piece, cast bulbous heads having an interior cavity that some manufacturers leave empty and others fill with a foam. The use of metal gives manufacturers precise control over the quality of the product and the location of weight throughout the head, properties that were often lacking in the drivers constructed of wood.
Because of the continuing popularity of the sport, there is ongoing effort to develop clubs with superior response.
In Anderson et al., U.S. Pat. No. 5,255,918 the inventor discloses an iron that has a cast head with a rimmed recess that can receive a separately formed face plate. This permits the use of forged, hardened, face plates and easily cast bodies. In Anderson, the cast head includes a planar web that closes the back of the recess. Accordingly, when the front plate is attached to the head a substantial space is formed between the web and the face plate. As noted in the patent, the space allows the face plate 21 to deflect rearward during impact with a golf ball.
Additionally, golf shots are most effective when the ball and club meet at the club's center of percussion, defined as a point where an impulsive force can be applied with no reaction force at the point of support. An area around the center of percussion is referred to as a "sweet spot." Many research and development efforts attempt to enlarge the sweet spot so that a club is more forgiving when a ball is slightly mis-hit.